Effects of different frequencies of conventional transcutaneous electrical nerve stimulation on pressure pain threshold and tolerance.

BACKGROUND: Pulse frequency is one of the key determinants of analgesic outcomes by transcutaneous electrical nerve stimulation (TENS). However, optimal settings remain unclear. OBJECTIVE: To compare the effects of different frequencies of TENS, on pressure pain threshold and tolerance. METHODS: Currents with pulse duration of 110 µs, and pulse frequencies of 60 pps or 150 pps were applied on the volar aspects of the dominant forearms of 20 healthy volunteers, on two consecutive days, in a randomized order. Threshold and tolerance were measured at the beginning, after the 15th and 30th minutes of the applications, and 30 minutes after the applications. RESULTS: Pressure pain threshold and tolerance values were higher at the 150 pps frequency, at all measurement times (p< 0.05). However, no frequencyXtime interaction and time-dependent changes were found for the outcome measures (p> 0.05). CONCLUSIONS: These findings established that, at 150 pps conventional TENS, threshold and tolerance values were consistently higher. These results are presented to inform future research regarding optimal conventional TENS parameters and to provide support for clinical applications.

Effects of thermal agents on electrical sensory threshold and current tolerance when applied prior to neuromuscular electrical stimulation.

BACKGROUND AND OBJECTIVE: This study aimed to investigate the effects of thermal agents on electrical sensory threshold and current tolerance when applied prior to neuromuscular electrical stimulation. METHODS: In this single-blind and cross-over trial, electrical sensory threshold and current tolerance of 24 healthy volunteers were evaluated by using biphasic symmetrical pulses (240 µsec, 50 pps), before and after thermal agent (cold pack, hot pack and ultrasound) applications. RESULTS: Electrical sensory threshold increased after cold-pack, and current tolerance reduced after hot-pack applications (p< 0.05). Inter-agent comparisons of pre and post-application differences of the investigated parameters revealed that the most obvious effects were caused by application of hot pack. CONCLUSIONS: Hot pack application prior to neuromuscular electrical stimulation (NMES) may reduce current tolerance and limit to reach the desired current intensity for strengthening the electrically induced contractions. Results are considered to be valuable for physiotherapists, who apply thermal agents and NMES consecutively, in their treatment programs.

Short and long-term results of connective tissue manipulation and combined ultrasound therapy in patients with fibromyalgia.

OBJECTIVE: The aim of the study was to evaluate the short-term and 1-year follow-up results of connective tissue manipulation and combined ultrasound (US) therapy (US and high-voltage pulsed galvanic stimulation) in terms of pain, complaint of nonrestorative sleep, and impact on the functional activities in patients with fibromyalgia (FM). METHODS: This is an observational prospective cohort study of 20 female patients with FM. Intensity of pain, complaint of nonrestorative sleep, and impact of FM on functional activities were evaluated by visual analogue scales. All evaluations were performed before and after 20 sessions of treatment, which included connective tissue manipulation of the back daily, for a total of 20 sessions, and combined US therapy of the upper back region every other session. One-year follow-up evaluations were performed on 14 subjects. Friedman test was used to analyze time-dependent changes. RESULTS: Statistical analyses revealed that pain intensity, impact of FM on functional activities, and complaints of nonrestorative sleep improved after the treatment program (P < .05). CONCLUSION: Methods used in this study seemed to be helpful in improving pain intensity, complaints of nonrestorative sleep, and impact on functional activities in patients with FM.